gaines



UNITED-STA r. cranves,` or MELROSE, TEXAS.

j. DRESSING MILLsToNEs.

. Specification of(` Letters Patent N o. "7,980,` dated `March 4,. 1851.

To all whom timmy `conce/m7,:

`Be it known that I,"EDMUND.P`. GAINES, of the county of Nacogdoches and State of Texas, have invented a new and improved mode o-f dressing millstones used for the purposeof grinding every kindof grain into meal flour &c., &c., and I do hereby declare that the` following is a full and exact description thereof, reference being had to the accompanying drawings and` to the letters of reference marked thereon. n

` To enable others skilled inthe art `to make and use my invention, I will proceed to describe its Construction and operation.

I take the upper` and lower mill stone which I intend to operate upon and grind the faces that are to be dressed perfectly smooth and even, lthe object being to make each of thesefaces abut. In geometry, it is termed a plane. `This is done by grinding sand and water through them until their faces assume this shape. By use of dividers, &c., I (by diameters or straight lines drawn through the center and, terminating in the circumference on each side) divide the face into equal parts. (In this instance the model from whichthe drawing is taken being a small one I divided the face into only eight parts.) The number of these varies withthe diameter of the plane. The stones having the largest diameters `may be divided into as many` as `eighteen equal parts.`

I then make a curved; rule as represented in the drawing bywhich the work upon the face of the stone is laid off or measured. The concave side of this rule must in every instance `have the same curvature as the circumference of the stone, the face `of which you intend to measure by it. Or in other words the mill stone and this curve must, in all cases, have the same or an equal radius. This rule is made just long enough to reach from the circumference to the eye of the stone. in measuring it. In making measurements the broadest end of this rule is always placed at the circumference and the other at, or toward, the eye. At the circumference this rule is about one eighth part broader than it is at the eye and it gradually becomes smaller from the one end to the other. The convex and concave sides of the rule have the same curvature; or in other words their radius is the same. The broadest ends of these rules vary from one inch to two inches and a quarter wide. Their size is Alarge or small in .proportion` to that of the diameter' of the stone to be dressed.

The principal or master `furrows (for I so designate them) (on. the face of thestone are laid off and madethus. `For example upon thediameter .a a place the letter `et upon the rule on the letter a at the `circum-` ference, and b upon` the rule on b at the` eye, and mark ofi" the size and figure or shape of the rule upc-n the stone. This is to `be thefsize of the furrow and its shape. You `then cut `your furrow `on the convex side or line of the rule from one quarter of an inch to an inch in depth. `The depth of this `is in proportion to the diameter ofthe stone. The furrow along the line of this convex side is almost perpendicular'. The furrow however is a little narrower than'it would be, if this side were entirely perpendicular. From the lowest part of this furrow (along the whole of its length) to the linelon thesurface drawn` upon ,the concave side of the rule, the furrow has the same curvature as the rule itself. This furrowis deeper by about one eighth part at the circumference than it is at the eye; its depth as you pass `toward the eye, `be.- coming gradually less. A furrow to be made inthe sameway on each one of the aforesaid eight times or more asV the site of the `diameter of the stone may require.

`And generally there are to be as many master furrows as there are parts into which the stone is divided; and one of these must be made as described above `on each ofthe lines dividing it. Asmall portion of the hollow of each of' these furrows is cut out at the `eye in order that they may be enabled better to receive the grain.

After you have completed those,fthen take your rule and place its concave side on the concave lineof the `master furrow and mark off .its size upon the surface, Then place the concave side of the rule on the line which` convex line of the master furrow and mark oif its size again upon the Stone (it will t be found that `the end of this, next to the eye, will pull upon a master furrow). Upon the size ofthe rule marked od' last you next make a furrow on the plan upon which you made the others. This is called a sho-rt furrow. The end of this, next to the eye, will not be exactly like a master furrow was made, for it will there intersect one of them. But the object is to make it as near like the first as it can be made. y The lower edge of this furrow is continued on to the lower 0r back edge of the master furrow. The rest of them arev laid off and made in the same way.

Upon the smooth surface (of the size of the rule) which is now left between each master and short furrow you must cut small grooves, from seven to twelve in number, (corresponding to the size of the rule). These are to run from the circumference to the eye of the stone. They are to be from one sixteenth to one eighth of an inch deep (their depth to be in direct proportion to the diameter of the stone) and they are to be as nearly parallel as they can be made to the curved edges of the rule. On the equal number of triangular surfaces, which will be now left, you must cut one groove along the line which is next to the edge of the master furrow, so as to preserve that edge. And then you must cut one through the center of the triangle, so as to run from its acute angle to the middle of its circum ference. Then cut grooves like those above on each side of this and parallel to it, until they cover the whole of the triangle. Before these grooves are cut they are laid ofll by the curve of the rule. You, of course, dress each of these triangles precisely in the same way. Vhen you may wish to dress, on this plan, stones that have been dressed on any other, you in the first place render their faces smooth and even in the manner directed above.

The annexed drawing and description given above is supposed to be the bed or bottom stone of the mill. The upper stonel or runner is made precisely in the same way. But it is easily seen that when this top stone is inverted and placed upon the lower one, the curvature of its lines will be reversed. When the mill is running, the

, convex curves of the upper stone or runner are in front.

. It will be seen that about one-half of each master furrow next to the eye is behind the diameter upon which it is made. The reverse of this is true in relation to the other half situated next to the circumfer-l ence. It will be also seen that the short furrow has, next to the circumference, double the draft or inclination of the master furrow. These furrows are so constructed as to retain nearly all of the grain near to the eye or centre of the stone, until it is ground into meal or flour. Mills dressed upon other plans grind the grain nearer to their circumferences. This, upon the principle of the common lines, gives them much greater resistance when grinding, than are to be overcome uponthe plan here proposed. Gnthis plan the furrows receive the grain and make it into hominy or small particles so the face can receive it and grind it into meal. In other plans the stones are made hollow on the entire surface near the eye (which by millers is termed the bosom) and this receives the grain and passes it off toward the circumference where it is ground.

Each one of the grooves described above shea-rs or cuts an equal quantity of grain to that sheared or cut by the curved edge of a furrow. This as numerous experiments prove, enables the plan proposed, with an equal power, to grind, in a given time, say three or four` times the amount of grain, that can be ground upon any other plan now in use. The grooves, which are used in no other plan) separates the bran from the meal or flour much more effectually and with much more ease to the machine than is done upon any other plan and the yield is consequently greater than in any other.

Mills dressed in this manner can not be crowded or choked, hence it has no such limit to the quantity it can grind, in a given time as, from this cause, other mills have which are differently dressed. And it is believed that large stones dressed on this plan, and having a sutlicient power to move them, might grind one hundred bushels in one ho-ur. The shape and depth of the furrows and the principle of the drawing are such that the mill dressed in this plan will avoid heating the Hour however long you may continue to run it.

lhat I claim as my invention and desire to secure by Letters Patent is- The new and improved mode of dressing mill-stones which I have described above as fully and correctly as I can.

E. P. GAINES.

Witnesses:

JOHN W. HARRIS, DANIEL D. CULP. 

